Display device with touch detection function and electronic apparatus

ABSTRACT

According to an aspect, a display device with a touch detection function includes a controller, touch wiring that supplies a touch drive signal to drive electrodes, and a plurality of switch groups that are provided for each of the drive electrodes, each of the plurality of switch groups having selection switches. The plurality of switch groups select a drive electrode to be coupled to a touch wiring based on a selection signal from the controller. The selection switches for each of the plurality of switch groups are coupled in parallel with each other between a corresponding drive electrode and the touch wiring, and for each of the drive electrodes, all of the selection switches operate in accordance with the selection signal, couple the corresponding drive electrodes and the touch wiring, and apply the touch drive signal to the corresponding drive electrodes.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 15/806,875, filed on Nov. 8, 2017, which is acontinuation of U.S. patent application Ser. No. 14/152,052, filed onJan. 10, 2014, now U.S. Pat. No. 9,836,168 issued on Dec. 5, 2017, whichclaims priority to Japanese Priority Patent Application JP 2013-003005filed in the Japan Patent Office on Jan. 10, 2013, and JP 2014-001530filed in the Japan Patent Office on Jan. 8, 2014, the entire content ofwhich is hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a display device and electronicapparatus capable of detecting an externally approaching object, andmore particularly, to a display device with a touch detection functionand an electronic apparatus capable of detecting an externallyapproaching object based on a change in electrostatic capacitance.

2. Description of the Related Art

Recently, much attention has been paid to a touch detection device,which is called touch panel, capable of detecting an externallyapproaching object. The touch panel is used for a display device with atouch detection function in which the touch detection device is attachedonto or integrated with display device such as liquid crystal displaydevice. The display device with a touch detection function enable thetouch panel to be used for information input as substitutes forconventional mechanical buttons by displaying various button images onthe display device. The display device with a touch detection functionhaving such touch panel requires no input devices such as a keyboard, amouse, and a keypad, thereby tending to be widely used for a portableinformation terminal such as a portable phone in addition to a computer.

There are several touch detection methods such as optical method,resistive method, and electrostatic capacitance method used for thetouch detection device. The touch detection device using theelectrostatic capacitance method has relatively simple structures andcan achieve low power consumption device when used in the portableinformation terminal, for example. For example, Japanese PatentApplication Laid-open Publication No. 2012-221485 (JP-A-2012-221485)discloses an electrostatic capacitive touch panel.

In the display device with a touch detection function, which integratetherein a display function and a touch detection function, an operationfor detecting a touch may influence the display, for example. Thedisplay panel with a touch detection function (display device with atouch detection function) disclosed in JP-A-2012-221485 can reduce theinfluence on the display due to the touch detection. The display panelwith a touch detection function disclosed in JP-A-2012-221485 includes adrive unit that selectively applies a direct-current drive signal VcomDCor an alternating-current drive signal VcomAC to a drive electrode. Inthe display panel with a touch detection function, the drive signal isapplied to the drive electrode and a signal according to the drivesignal is output from a touch detection electrode while a displayelement is display-driven. Two wiring for supplying the direct-currentdrive signal VcomDC and the alternating-current drive signal VcomAC tothe drive electrode thus need to be routed in a frame area.

The display panel with a touch detection function disclosed inJP-A-2012-221485 includes a selection switch that selectively suppliesthe direct-current drive signal VcomDC and the alternating-current drivesignal VcomAC to the drive electrode through the two wiring. In thedisplay panel with a touch detection function disclosed inJP-A-2012-221485, the interconnection resistance in the selection switchmay influence a time constant of a waveform of the drive signal. Theselection switch, thus, needs to be enlarged in order to reduce theinterconnection resistance thereof. The increase in the size of theselection switch may enlarge the frame area, which does not contributeto function as a display area.

For the foregoing reasons, there is a need for a display device with atouch detection function and an electronic apparatus capable of reducingthe interconnection resistance of the selection switch that selects adrive electrode to which the drive signal is applied and capable ofreducing the frame in size.

SUMMARY

According to an aspect, a display device with a touch detection functionincludes: a display area including a plurality of pixel electrodesarranged in a matrix on a substrate; a plurality of drive electrodesthat are disposed to face the plurality of pixel electrodes; a displayfunction layer that has an image display function to display an image inthe display area; a controller that performs image display control tofulfill the image display function of the display function layer byapplying a display drive voltage between the plurality of pixelelectrodes and the plurality of drive electrodes based on an imagesignal; a plurality of touch detection electrodes that face theplurality of drive electrodes, and form an electrostatic capacitancebetween the plurality of drive electrodes and the plurality of touchdetection electrodes; a touch detection unit that detects a position ofan approaching object based on a detection signal from the plurality oftouch detection electrodes; touch wiring that is routed in a frame arealocated outside the display area and supplies a touch drive signal tothe plurality of drive electrodes; and a plurality of switch groups thatare provided for each of the plurality of drive electrodes, each of theplurality of switch groups having a plurality of selection switches thatoperate based on a selection signal from the controller. The pluralityof switch groups select a drive electrode to be coupled to the touchwiring from the plurality of drive electrodes based on a selectionsignal from the controller, and the plurality of selection switches foreach of the plurality of switch groups are coupled in parallel with eachother between a corresponding drive electrode and the touch wiring, andfor each of the plurality of drive electrodes, all of the plurality ofselection switches operate in accordance with the selection signal,couple the corresponding drive electrodes and the touch wiring, andapply the touch drive signal to the corresponding drive electrodes.

According to another aspect, an electronic apparatus has a displaydevice with a touch detection function capable of detecting anexternally approaching object. The display device with a touch detectionfunction includes: a display area including a plurality of pixelelectrodes arranged in a matrix on a substrate; a plurality of driveelectrodes that are disposed to face the plurality of pixel electrodes;a display function layer that has an image display function to displayan image in the display area; a controller that performs image displaycontrol to fulfill the image display function of the display functionlayer by applying a display drive voltage between the plurality of pixelelectrodes and the plurality of drive electrodes based on an imagesignal; a plurality of touch detection electrodes that face theplurality of drive electrodes, and form an electrostatic capacitancebetween the plurality of drive electrodes and the plurality of touchdetection electrodes; a touch detection unit that detects a position ofan approaching object based on a detection signal from the plurality oftouch detection electrodes; touch wiring that is routed in a frame arealocated outside the display area and supplies a touch drive signal tothe plurality of drive electrodes; and a plurality of switch groups thatare provided for each of the plurality of drive electrodes, each of theplurality of switch groups having a plurality of selection switches thatoperate based on a selection signal from the controller. The pluralityof switch groups select a drive electrode to be coupled to the touchwiring from the plurality of drive electrodes based on a selectionsignal from the controller, and the plurality of selection switches foreach of the plurality of switch groups are coupled in parallel with eachother between a corresponding drive electrode and the touch wiring, andfor each of the plurality of drive electrodes, all of the plurality ofselection switches operate in accordance with the selection signal,couple the corresponding drive electrodes and the touch wiring, andapply the touch drive signal to the corresponding drive electrodes.

Additional features and advantages are described herein, and will beapparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram illustrating an example of the configurationof a display device with a touch detection function according to a firstembodiment;

FIG. 2 is a diagram to explain a basic principle of an electrostaticcapacitance type touch detection method and a state where a finger doesnot come into contact with or approaches a device;

FIG. 3 is an explanatory diagram illustrating an example of anequivalent circuit of the state illustrated in FIG. 2;

FIG. 4 is a diagram to explain the basic principle of the electrostaticcapacitance type touch detection method and a state where a finger comesinto contact with or approaches a device;

FIG. 5 is an explanatory diagram illustrating an example of anequivalent circuit of the state illustrated in FIG. 4;

FIG. 6 is a schematic diagram illustrating an example of waveforms of adrive signal and a touch detection signal;

FIG. 7 is a schematic diagram illustrating an example of a module onwhich the display device with a touch detection function according tothe first embodiment is mounted;

FIG. 8 is a cross-sectional diagram illustrating a schematiccross-sectional structure of a display unit with a touch detectionfunction according to the first embodiment;

FIG. 9 is a schematic diagram illustrating an example of a controller ofthe display device with a touch detection function according to thefirst embodiment;

FIG. 10 is a circuit diagram illustrating a pixel arrangement of thedisplay unit with a touch detection function according to the firstembodiment;

FIG. 11 is a schematic diagram to explain a relation between a sourcedriver and a pixel signal line in the module on which the display devicewith a touch detection function according to the first embodiment ismounted;

FIG. 12 is a perspective view illustrating an example of theconfiguration of drive electrodes and touch detection electrodes of thedisplay unit with a touch detection function according to the firstembodiment;

FIG. 13 is a schematic diagram illustrating an operation example oftouch detection in the display device with a touch detection functionaccording to the first embodiment;

FIG. 14 is a schematic diagram illustrating the operation example of thetouch detection in the display device with a touch detection functionaccording to the first embodiment;

FIG. 15 is a schematic diagram illustrating the operation example of thetouch detection in the display device with a touch detection functionaccording to the first embodiment;

FIG. 16 is a schematic diagram to explain display operation and touchdetection operation in the display device with a touch detectionfunction according to the first embodiment;

FIG. 17 is a block diagram illustrating a drive signal generator of adrive electrode driver according to the first embodiment;

FIG. 18 is a block diagram illustrating the drive electrode driveraccording to the first embodiment;

FIG. 19 is a block diagram illustrating a drive unit of the driveelectrode driver according to the first embodiment;

FIG. 20 is a block diagram illustrating an arrangement example ofselection switches of the drive electrode driver according to the firstembodiment;

FIG. 21 is an explanatory diagram illustrating an example of timingwaves of the display device with a touch detection function;

FIG. 22 is an explanatory diagram illustrating an operation example oftouch detection scan;

FIG. 23 is a schematic diagram illustrating an example of the controllerof the display device with a touch detection function according to asecond embodiment;

FIG. 24 is a block diagram illustrating the drive unit of the driveelectrode driver according to the second embodiment;

FIG. 25 is a block diagram illustrating an arrangement example of theselection switches of the drive electrode driver according to the secondembodiment;

FIG. 26 is a block diagram illustrating the drive unit of the driveelectrode driver according to a third embodiment;

FIG. 27 is a block diagram illustrating an arrangement example of theselection switches of the drive electrode driver according to the thirdembodiment;

FIG. 28 is a cross-sectional diagram illustrating a schematiccross-sectional structure of the display unit with a touch detectionfunction according to a modification;

FIG. 29 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 30 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 31 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 32 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 33 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 34 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 35 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 36 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 37 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 38 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 39 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied;

FIG. 40 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied; and

FIG. 41 is a schematic diagram illustrating an example of an electronicapparatus to which the display device with a touch detection functionaccording to the embodiments is applied.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described below in detail withreference to the accompanying drawings. The description of the followingembodiments does not limit the present disclosure. The constituentelements of the following embodiments include elements easily envisagedby those skilled in the art and identical elements. The constituteelements described below can also be combined as appropriate. Thedescription will be made in the following order.

1. Embodiments (display device with a touch detection function)

1-1. First Embodiment

1-2. Second Embodiment

1-3. Third Embodiment

2. Application Examples (electronic apparatuses)

Examples in which the display device with a touch detection functionaccording to the embodiments mentioned above are applied to electronicapparatuses

3. Aspects of the Present Disclosure

1. Embodiments

1-1. First Embodiment

1-1A. Configuration Example

Overall Configuration Example

FIG. 1 is a block diagram illustrating an example of the configurationof a display device with a touch detection function according to a firstembodiment. A display device with a touch detection function 1 includesa display unit with a touch detection function 10, a control unit 11, agate driver 12, a source driver 13, a source selector 13S, a driveelectrode driver 14, and a touch detection unit 40. In the displaydevice with a touch detection function 1, the display unit with a touchdetection function 10 is a display device having a touch detectionfunction built therein. The display unit with a touch detection function10 is an in-cell type device in which a liquid crystal display unit 20using a liquid crystal element as a display element and an electrostaticcapacitance type touch detection device 30 are integrated. The displayunit with a touch detection function 10 may be an on-cell type device inwhich the electrostatic capacitance type touch detection device 30 isattached onto the liquid crystal display unit 20 using the liquidcrystal element as the display element.

The liquid crystal display unit 20 performs display by sequentiallyscanning each one horizontal line in accordance with a scan signal Vscansupplied from the gate driver 12, which is described later. The controlunit 11 supplies control signals to the gate driver 12, the sourcedriver 13, the drive electrode driver 14, and the touch detection unit40 based on a video signal Vdisp externally supplied so as to controlthe gate driver 12, the source driver 13, the drive electrode driver 14,and the touch detection unit 40 to operate in synchronization with eachother. The controller in the present disclosure includes the controlunit 11, the gate driver 12, the source driver 13, and the driveelectrode driver 14.

The gate driver 12 has a function of sequentially selecting onehorizontal line as a target of display driving of the display unit witha touch detection function 10, based on the control signal supplied fromthe control unit 11.

The source driver 13 is a circuit that supplies a pixel signal Vpix toeach pixel Pix (sub-pixel SPix), which is described later, of thedisplay unit with a touch detection function 10 based on the controlsignal supplied from the control unit 11. The source driver 13 generatesan image signal in which the pixel signals Vpix of a plurality ofsub-pixels SPix of the liquid display unit 20 are time-divisionmultiplexed from the video signal Vdisp for one horizontal line, andsupplies the generated image signal to the source selector 13S, which isdescribed later. The source driver 13 also generates a switch controlsignal Vsel necessary to separate the pixel signals Vpix multiplexed inan image signal Vsig from the image signal Vsig, and supplies the switchcontrol signal Vsel to the source selector 13S together with the pixelsignals Vpix. The source selector 13S can reduce the number of wiringbetween the source driver 13 and the control unit 11.

The drive electrode driver 14 is a circuit that supplies a drive signalVcomAC for touch detection (touch drive signal, hereinafter referred toas the drive signal) and a display drive voltage VcomDC serving as avoltage for displaying to a drive electrode COML, which is describedlater, of the display unit with a touch detection function 10 based onthe control signal supplied from the control unit 11.

The touch detection unit 40 is a circuit that detects existence of atouch (the touch conditions described below) on the touch detectiondevice 30 based on the control signal supplied from the control unit 11and a touch detection signal Vdet supplied from the touch detectiondevice 30 of the display unit with a touch detection function 10, andobtains the coordinates of the touch in a touch detected area when thetouch exists. The touch detection unit 40 includes a touch detectionsignal amplifier 42, an analog-digital (A/D) converter 43, a signalprocessor 44, a coordinate extraction unit 45, and a detection timingcontroller 46.

The touch detection signal amplifier 42 amplifies the touch detectionsignal Vdet supplied from the touch detection device 30. The touchdetection signal amplifier 42 may include a low pass analog filter thatremoves a high frequency component (noise component) included in thetouch detection signal Vdet and extracts touch components and outputsthe touch components.

Basic Principle of Electrostatic Capacitance Type Touch Detection

The touch detection device 30 operates based on the basic principle ofelectrostatic capacitance type touch detection and outputs the touchdetection signal Vdet. The following describes the basic principle oftouch detection in the display device with a touch detection function 1of the embodiment with reference to FIGS. 1 to 6. FIG. 2 is a diagram toexplain a basic principle of an electrostatic capacitance type touchdetection method and a state where a finger does not come into contactwith or approach a device. FIG. 3 is an explanatory diagram illustratingan example of an equivalent circuit of the state illustrated in FIG. 2.FIG. 4 is a diagram to explain the basic principle of the electrostaticcapacitance type touch detection method and a state where a finger comesinto contact with or approaches a device. FIG. 5 is an explanatorydiagram illustrating an example of the equivalent circuit of the stateillustrated in FIG. 4. FIG. 6 is a schematic diagram illustrating anexample of waveforms of the drive signal and the touch detection signal.

As illustrated in FIG. 2, a capacitive element C1 includes a pair ofelectrodes of a drive electrode E1 and a touch detection electrode E2,which are disposed to face each other with a dielectric substance Dinterposed therebetween, for example. As illustrated in FIG. 3, the oneend of the capacitive element C1 is coupled to an alternating-current(AC) signal source (drive signal source) S and the other end thereof iscoupled to a voltage detector (touch detection unit) DET. The voltagedetector DET is an integrating circuit included in the touch detectionsignal amplifier 42 illustrated in FIG. 1, for example.

When an alternating-current (AC) rectangular wave Sg having apredetermined frequency (e.g., from about several to several hundredkilohertz) is applied to the drive electrode E1 (the one end of thecapacitive element C1) from the AC signal source S, an output waveform(the touch detection signal Vdet) appears through the voltage detectorDET coupled on a side adjacent to the touch detection electrode E2 (theother end of the capacitive element C1). The AC rectangular wave Sgcorresponds to the drive signal VcomAC, which is described later.

In the state where a finger does not come into contact with (orapproach) a device (non-contact state), as illustrated in FIGS. 2 and 3,a current I₀ flows in accordance with a capacitance value of thecapacitive element C1 during the charging and discharging of thecapacitive element C1. The voltage detector DET illustrated in FIG. 3converts a change in current I₀ according to the AC rectangular wave Sginto a change in voltage (a waveform V₀ illustrated with the actual linein FIG. 6).

In the state where a finger comes into contact with (or approaches) adisplay (contact state), as illustrated in FIG. 4, the electrostaticcapacitance acts as a capacitive element C1′ having a smallercapacitance value than that of the capacitive element C1 because afringe component of the electrostatic capacitance between the driveelectrode E1 and the touch detection electrode E2 is blocked due to anelectrostatic capacitance C2, which is formed by the finger, comes intocontact with or exists near the touch detection electrode E2. Asillustrated in the equivalent circuit in FIG. 5, a current I₁ flows inthe capacitive element C1′. As illustrated in FIG. 6, the voltagedetector DET converts a change in current I₁ according to the ACrectangular wave Sg into a change in voltage (a waveform V₁ illustratedwith the dotted line). In this case, the amplitude of the waveform V₁ issmaller than that of the waveform V₀. The absolute value |ΔV| of adifference in voltage between the waveform V₀ and the waveform V₁changes in accordance with the influence of an externally approachingobject such as a finger. The voltage detector DET preferably operateswith a time period of Reset in which the charging and discharging of thecapacitor is reset by switching in the circuit in synchronization withthe frequency of the AC rectangular wave Sg so as to accurately detectthe absolute value |ΔV| of a difference in voltage between the waveformV₀ and the waveform V₁.

The touch detection device 30 illustrated in FIG. 1 performs touchdetection by sequentially scanning each one detection block inaccordance with a drive signal Vcom (the drive signal VcomAC, which isdescribed later) supplied from the drive electrode driver 14.

The touch detection device 30 outputs the touch detection signal Vdetfrom a plurality of touch detection electrodes TDL to be described laterfor each detection block through the voltage detector DET illustrated inFIG. 3 or 5, and thereby supplying the touch detection signal Vdet tothe A/D converter 43 of the touch detection unit 40.

The A/D converter 43 is a circuit that samples respective analog signalsoutput from the touch detection signal amplifier 42 and converts theanalog signals into digital signals in synchronization with the drivesignal VcomAC.

The signal processor 44 includes a digital filter that reduces afrequency component (noise component), which excludes the samplingfrequency of the drive signal VcomAC, included in the output signalsfrom the A/D converter 43. The signal processor 44 is a logic circuitthat detects the existence of a touch on the touch detection device 30based on the output signals from the A/D converter 43. The signalprocessor 44 only extracts the voltage difference caused by a finger.The voltage difference caused by a finger is the absolute value |ΔV| ofthe voltage difference between the waveform V₀ and the waveform V₁. Thesignal processor 44 may perform an arithmetic operation to average theabsolute values |ΔV| per detection block and obtain the average of theabsolute values |ΔV|. As a result, the signal processor 44 can reducethe influence due to noise. The signal processor 44 compares thedetected voltage difference caused by a finger with a predeterminedthreshold voltage and determines that it is in the contact state with anexternally approaching object when the voltage difference is equal to orlarger than the threshold voltage. The signal processor 44 determinesthat it is in the non-contact state with an external approaching objectwhen the voltage difference is smaller than the threshold voltage. Inthis way, the touch detection unit 40 can perform the touch detection.

The coordinate extraction unit 45 is a logic circuit that obtains touchpanel coordinates of the touch when the touch is detected by the signalprocessor 44. The detection timing controller 46 controls the A/Dconverter 43, the signal processor 44, and the coordinate extractionunit 45 to be operated in synchronization with each other. Thecoordinate extraction unit 45 outputs the touch panel coordinates as asignal output Vout.

Module

FIG. 7 is a schematic diagram illustrating an example of a module onwhich the display device with a touch detection function according tothe first embodiment is mounted. As illustrated in FIG. 7, the displaydevice with a touch detection function 1 includes a pixel substrate 2 (athin film transistor (TFT) substrate 21), which is described later, anda flexible printed circuit substrate T. The pixel substrate 2 (TFTsubstrate 21) has a chip on glass (COG) 19 mounted thereon and a displayarea Ad of the liquid crystal display unit and frames Gd formed thereon.The COG 19 is an integrated circuit (IC) driver chip mounted on the TFTsubstrate 21 and is a controller that includes the circuits necessaryfor display operation, such as the control unit 11 and the source driver13 illustrated in FIG. 1. In the embodiment, the source driver 13 andthe source selector 13S are formed on the TFT substrate 21. The sourcedriver 13 and the source selector 13S may be built into the COG 19.Drive electrode scan units 14A and 14B, which are included in the driveelectrode driver 14, are formed on the TFT substrate 21. The gate driver12 is formed on the TFT substrate 21 as gate drivers 12A and 12B. Thedisplay device with a touch detection function 1 may build the circuitssuch as the drive electrode scan units 14A and 14B and the gate driver12 into the COG 19.

As illustrated in FIG. 7, drive electrode blocks B composed of the driveelectrode COML and the touch detection electrodes TDL are formed suchthat they intersect with each other in a grade separation manner in adirection perpendicular to the surface of the TFT substrate 21.

The drive electrodes COML is a plurality of stripe electrode patternsextending in one direction. In the touch detection operation, the drivesignal VcomAC is sequentially applied to the respective electrodepatterns by the drive electrode driver 14. The drive electrode block Billustrated in FIG. 7 is the plurality of stripe electrode patterns ofthe drive electrodes COML, to which patterns the drive signal VcomAC issupplied in parallel. The drive electrode blocks B (drive electrodesCOML) are formed in the long side direction of the display unit with atouch detection function 10, whereas the touch detection electrodes TDL,which are described later, are formed in the short side direction of thedisplay unit with a touch detection function 10. The output ends of thetouch detection electrodes TDL are coupled to the touch detection unit40, which is mounted on the flexible printed circuit substrate T andprovided on the short side of the display unit with a touch detectionfunction 10, through the flexible printed circuit substrate T. In thisway, the touch detection unit 40 is mounted on the flexible printedcircuit substrate T and coupled to the respective touch detectionelectrodes TDL arranged in parallel with each other. The flexibleprinted circuit substrate T is only required to function as a terminaland thus is not limited to the flexible printed circuit substrate. Whensuch a terminal is used, the touch detection unit 40 is provided outsidethe module.

A drive signal generator, which is described later, is built into theCOG 19. The source selector 13S is formed using TFT elements in thevicinity of the display area Ad on the TFT substrate 21. In the displayarea Ad, a large number of pixels Pix, which are described later, arearranged in a matrix (in rows and columns). The frames Gd are areas inwhich no pixels Pix are arranged when viewed from the directionperpendicular to the surface of the TFT substrate 21. The gate driver 12and drive electrode scan units 14A and 14B included in the drive driver14 are arranged in the frames Gd.

The gate driver 12, which includes the gate drivers 12A and 12B, isformed on the TFT substrate 21 using TFT elements. The gate drivers 12Aand 12B can drive the sub-pixels SPix (pixels), which are describedlater, arranged in a matrix in the display area Ad from both sides ofthe display area Ad interposed therebetween. In the followingdescription, the gate driver 12A is referred to as a first gate driver12A while the gate driver 12B is referred to as a second gate driver12B. Scan lines GCL, which are described later, are arranged between thefirst gate driver 12A and the second gate driver 12B. Thus, the scanlines GCL are provided, in the direction perpendicular to the surface ofthe TFT substrate 21 (on-above the TFT substrate 21), such that theyextend in a direction in parallel with the extending direction of thedrive electrode COML.

The drive electrode scan units 14A and 14B are formed on the TFTsubstrate 21 using TFT elements. The drive electrode scan units 14A and14B each receive the display drive voltage VcomDC through display wiringLDC and the drive signal VcomAC through touch wiring LAC from the drivesignal generator. The drive electrode scan units 14A and 14B each occupya predetermined width Gdv in the frame Gd. The drive electrode scanunits 14A and 14B can drive the respective drive electrode blocks Barranged in parallel with each other from both sides of the respectivedrive electrode blocks B. The display wiring LDC supplying the displaydrive voltage VcomDC and the touch wiring LAC supplying the touch drivesignal VcomAC are arranged in parallel with each other in each frame Gd.The display wiring LDC is disposed on a side closer to the display areaAd than the touch wiring LAC. This arrangement causes the display drivevoltage VcomDC supplied by the display wiring LDC to stabilize apotential condition at the end portion of the display area Ad. As aresult, in particular, a liquid crystal display device using a liquidcrystal of a lateral electric field mode performs a stable display.

The display device with a touch detection function 1 illustrated in FIG.7 outputs the touch detection signal Vdet from a side adjacent to theshort side of the display unit with a touch detection function 10. As aresult, the display device with a touch detection function 1 makes itpossible to readily route the wiring when the display unit with a touchdetection function 10 is coupled to the touch detection unit 40 throughthe flexible printed circuit substrate T serving as the terminal unit.

Display Device With a Touch Detection Function

The following describes a configuration example of the display unit witha touch detection function 10 in detail. FIG. 8 is a cross-sectionaldiagram illustrating a schematic cross-sectional structure of thedisplay unit with a touch detection function according to the firstembodiment. FIG. 9 is a schematic diagram illustrating an example of thecontroller of the display device with a touch detection functionaccording to the first embodiment. FIG. 10 is a circuit diagramillustrating a pixel arrangement of the display unit with a touchdetection function according to the first embodiment.

As illustrated in FIG. 8, the display unit with a touch detectionfunction 10 includes the pixel substrate 2, a counter substrate 3disposed to face the pixel substrate 2 in the direction perpendicular tothe surface of the pixel substrate 2, and a liquid crystal layer 6interposed between the pixel substrate 2 and the counter substrate 3.

The liquid crystal layer 6 modulates light passing through the liquidcrystal layer 6 in accordance with the state of an electric field. Aliquid crystal of a lateral electric field mode such as a fringe fieldswitching (FFS) or an in-plane switching (IPS) mode is used for theliquid crystal display device, for example. Alignment films may bedisposed between the liquid crystal layer 6 and the pixel substrate 2and between the liquid crystal layer 6 and the counter substrate 3 inFIG. 8.

The counter substrate 3 includes a glass substrate 31 and a color filter32 formed on the one surface of the glass substrate 31. On the othersurface of the glass substrate 31, the touch detection electrodes TDLserving as the detection electrodes of the touch detection device 30 areformed. In addition, a polarizing plate 35 is disposed on the touchdetection electrodes TDL.

The pixel substrate 2 includes the TFT substrate 21 as a circuitsubstrate, a plurality of pixel electrodes 22 arranged in a matrix onthe TFT substrate 21, the a plurality of drive electrodes COML formedbetween the TFT substrate 21 and the pixel electrodes 22, and aninsulation layer 24 that isolates the pixel electrodes 22 and the driveelectrodes COML.

System Configuration Example of Display Apparatus

The pixel substrate 2 includes the display area Ad, the COG 19 havingfunctions of an interface (I/F) and a timing generator, the first gatedriver 12A, the second gate driver 12B, and the source driver 13 on theTFT substrate 21. The flexible printed circuit substrate T illustratedin FIG. 7 transmits external signals or drive power driving the COG 19to the COG 19 illustrated in FIGS. 7 and 9. The pixel substrate 2includes, at the surface of the TFT substrate 21 of a transparentinsulation substrate (e.g., a glass substrate), the display area Ad inwhich a large number of pixels including liquid crystal cells arearranged in a matrix (rows and columns), the source driver (horizontaldrive circuit) 13, and the gate drivers (vertical drive circuits) 12Aand 12B. The gate drivers (vertical drive circuits) 12A and 12B arearranged as the first gate driver 12A and the second gate driver 12Bwith the display area Ad interposed therebetween.

The display area Ad has a matrix (row-column) structure in which thesub-pixels SPix including liquid crystal layers are arranged in m rows×ncolumns. In this specification, the term row means the pixel row havingm sub-pixels SPix arranged in one direction. The term column means thepixel column including n sub-pixels SPix arranged in a directionperpendicular to the extending direction of the pixel row. The values ofm and n are determined in accordance with a display resolution in thevertical direction and the display resolution in the horizontaldirection. In the display area Ad, scan lines GCL_(m+1), GCL_(m+2),GCL_(m+3), and so on are wired for the respective rows and signal linesSGL_(n+1), SGL_(n+2), SGL_(n+3), SGL_(n+4), SGL_(n+5), and so on arewired for the respective columns in the m-row, n-column matrix of thepixels Vpix. In the embodiment, the scan lines GCL_(m+1), GCL_(m+2),GCL_(m+3), and so on may be collectively described as the scan line GCLwhile the signal lines SGL_(n+1), SGL_(n+2), SGL_(n+3), SGL_(n+4),SGL_(n+5), and so on may be collectively described as the signal lineSGL.

The pixel substrate 2 receives externally a master clock, a horizontalsynchronizing signal, and a vertical synchronizing signal as externalsignals and they are applied to the COG 19. The COG 19 converts theamplitudes of the master clock, the horizontal synchronizing signal, andthe vertical synchronizing signal that have the voltage amplitude of anexternal power source into the voltage amplitude of an internal powersource necessary to drive the liquid crystal (performs level conversionor voltage boosting). Thereafter, the COG 19 inputs them to a timinggenerator as the master clock, the horizontal synchronizing signal, andthe vertical synchronizing signal to generate a vertical start pulseVST, a vertical clock pulse VCK, a horizontal start pulse HST, and ahorizontal clock pulse HCK. The COG 19 applies the vertical start pulseVST and the vertical clock pulse VCK to the first gate driver 12A andthe second gate driver 12B, while applying the horizontal start pulseHST and the horizontal clock pulse HCK to the source driver 13. The COG19 generates a display drive voltage (counter electrode potential) VCOMand applies it to the drive electrode COML. The display drive voltageVCOM is applied, in common, for the pixel electrodes of the respectivesub-pixels SPix and is called common potential.

The first gate driver 12A and the second gate driver 12B include shiftregisters, which are described later, and may further include latchcircuits. When the first gate driver 12A and the second gate driver 12Breceive the vertical start pulse VST, the respective latch circuitssequentially sample and latch display data output from the COG 19 in onehorizontal period in synchronization with the vertical clock pulse VCK.The first gate driver 12A and the second gate driver 12B sequentiallyoutput the digital data of one line latched by the latch circuit as avertical scan pulse and apply the data to the scan line GCL, therebysequentially selecting the sub-pixels SPix row by row. The first gatedriver 12A and the second gate driver 12B are arranged with the scanline GCL interposed therebetween in the extending direction of the scanline GCL. The first gate driver 12A and the second gate driver 12Bsequentially output the vertical scan pulse from the upper side of thedisplay area Ad, that is the upper side in the vertical scan directionto the lower side of the display area Ad, that is the lower side in thevertical scan direction.

The digital image signal Vsig of 6-bit R (red) G (green) B (blue) isapplied to the source driver 13, for example. The source driver 13writes the display data into the respective sub-pixels SPix selected bythe vertical scan of the first gate driver 12A and the second gatedriver 12B for each pixel, pixels by pixels, or all pixels at oncethrough the signal line SGL.

On the TFT substrate 21, formed are TFT elements Tr of the respectivesub-pixels SPix illustrated in FIGS. 9 and 10, and the wiring such asthe pixel signal line SGL supplying the pixel signal Vpix to therespective pixel electrodes 22 illustrated in FIG. 8, and the scan lineGCL driving the respective TFT elements Tr. The pixel signal line SGLextends on the plane in parallel with the surface of the TFT substrate21 and supplies the pixel signal Vpix to the pixels to display images.The liquid crystal display unit 20 illustrated in FIG. 10 includes theplurality of sub-pixels SPix arranged in a matrix. Each sub-pixel SPixincludes the TFT element Tr and a liquid crystal element LC. The TFTelement Tr is a thin film transistor. In this example, the TFT elementTr is an n-channel metal oxide semiconductor (MOS) type TFT. The sourceof the TFT element Tr is coupled to the pixel signal line SGL, the gatethereof is coupled to the scan line GCL, and the drain thereof iscoupled to one end of the liquid crystal element LC. The one end of theliquid crystal element LC is coupled to the drain of the TFT element Trand the other end thereof is coupled to the drive electrode COML.

The first gate driver 12A and the second gate driver 12B illustrated inFIG. 9 apply the vertical scan pulse to the gates of the TFT elements Trof the respective sub-pixels SPix through the scan line GCL illustratedin FIG. 10 and thus sequentially select one row (one horizontal line) ofthe sub-pixels SPix arranged in a matrix in the display area Ad as thetarget of the display drive. The source driver 13 supplies, through thepixel signal line SGL, pixel signal Vpix to the respective sub-pixelsSPix included in the horizontal line sequentially selected by the firstgate driver 12A and the second gate driver 12B. The sub-pixels SPixserving as the display targets perform a display of one horizontal linein accordance with the supplied pixel signal. The drive electrode driver14 drives the drive electrode COML by applying the display drive signal(display drive voltage VcomDC) thereto.

As described above, the display device with a touch detection function 1drives the first gate driver 12A and the second gate driver 12B so as tosequentially scan the scan lines GCL_(m+1), GCL_(m+2), GCL_(m+3), and soon, thereby sequentially selecting one horizontal line. In the displaydevice with a touch detection function 1, the source driver 13 suppliesthe pixel signal to the respective pixels Vpix included in onehorizontal line, thereby causing a display to be performed in units ofone horizontal line. In the display operation, the drive electrodedriver 14 applies the drive signal Vcom to the drive electrode COMLcorresponding to the horizontal line.

The color filter 32 illustrated in FIG. 8 is composed of color filtersthat are colored in the respective three colors of red (R), green (G),and blue (B) and periodically arranged, for example. A set of colorareas 32R, 32G, and 32B of the three colors of RGB (refer to FIG. 10)provided to the respective sub-pixels SPix corresponds to the pixel Pix.The color filter 32 faces the liquid crystal layer 6 in the directionperpendicular to the TFT substrate 21. The combination of colors in thecolor filter 32 may differ from this example as long as different colorsare combined.

The sub-pixels SPix illustrated in FIG. 10 are coupled to each other inthe same row of the liquid crystal display unit 20 through the scan lineGCL. The scan line GCL is coupled to the gate driver 12, which suppliesthe scan signal Vscan to the scan line GCL. The sub-pixels SPix arecoupled to each other in the same column of the liquid crystal displayunit 20 through the pixel signal line SGL. The pixel signal line SGL iscoupled to the source driver 13, which supplies the pixel signal Vpix tothe pixel signal line SGL.

FIG. 11 is a schematic diagram to explain a relation between the sourcedriver and the pixel signal line in the module on which the displaydevice with a touch detection function according to the first embodimentis mounted. As illustrated in FIG. 11, in the display device with atouch detection function 1, the pixel signal line SGL is coupled to thesource driver 13 included in the COG 19 through the source selector 13S.The source selector 13S performs open-close operation in accordance withthe switch control signal Vsel.

As illustrated in FIG. 11, the source driver 13 generates the pixelsignal Vpix based on the image signal Vsig and the source driver controlsignal supplied from the control unit 11 and outputs the pixel signalVpix. The source driver 13 generates the image signal in which the pixelsignal Vpix for the sub-pixels SPix (in this case, three sub-pixelsSPix) of the liquid crystal display unit 20 of the display unit with atouch detection function 10 are time-division multiplexed from the imagesignal Vsig for one horizontal line, and supplies the generated imagesignal to the source selector 13S. The source driver 13 also generatesthe switch control signal Vsel (VselR, VselG, and VselB) necessary toseparate the pixel signal Vpix multiplexed in the image signal Vsig andsupplies the switch control signal Vsel to the source selector 13Stogether with the image signal Vsig. The multiplexing reduces the numberof wiring between the source driver 13 and the source selector 13S.

The source selector 13S separates, from the image signal Vsig, the pixelsignal Vpix time-division multiplexed in the image signal Vsig based onthe image signal Vsig and the switch control signal Vsel supplied fromthe source driver 13, and supplies the separated pixel signal Vpix tothe liquid crystal display unit 20 of the display unit with a touchdetection function 10.

The source selector 13S includes three switches SWR, SWG, and SWB, forexample. The respective one ends of the switches SWR, SWG, and SWB arecoupled to each other, through which the image signal Vsig is suppliedfrom the source driver 13. The respective other ends of the switchesSWR, SWG, and SWB are coupled to the respective corresponding sub-pixelsSPix through the pixel signal line SGL of the liquid crystal displayunit 20 of the display unit with a touch detection function 10. Theswitches SWR, SWG, and SWB are controlled to be opened or closed by theswitch control signal Vsel (VselR, VselG, and VselB, respectively)supplied from the source driver 13. This configuration enables thesource selector 13S to sequentially turn on the switches SWR, SWG, andSWB in a time-division multiplexing manner in accordance with the switchcontrol signal Vsel. As a result, the source selector 13S separates,from the multiplexed image signal Vsig, the pixel signal Vpix (VpixR,VpixG, and VpixB). The source selector 13S then supplies the pixelsignal Vpix to the respective three sub-pixels SPix. The color areas32R, 32G, and 32B colored in red (R), green (G), and blue (B) correspondto the respective sub-pixels SPix. The pixel signal VpixR is supplied tothe sub-pixel SPix corresponding to the color area 32R. The pixel signalVpixG is supplied to the sub-pixel SPix corresponding to the color area32G. The pixel signal VpixB is supplied to the sub-pixel SPixcorresponding to the color area 32B.

The sub-pixels SPix are coupled to each other in the same row of theliquid crystal display unit 20 through the drive electrode COML. Thedrive electrode COML is coupled to the drive electrode driver 14, whichsupplies the display drive voltage VcomDC to the drive electrode COML.In the embodiment, the multiple sub-pixels SPix included in the same rowhave the common drive electrode COML.

The gate driver 12 illustrated in FIG. 1 applies the scan signal Vscanto the gates of the TFT elements Tr of the respective sub-pixels SPixthrough the scan line GCL illustrated in FIG. 10, and thus sequentiallyselects one row (one horizontal line) of the sub-pixels SPix arranged ina matrix in the liquid crystal display unit 20 as the target of thedisplay drive. The source driver 13 illustrated in FIG. 1 supplies thepixel signal Vpix to the respective sub-pixels SPix included in thehorizontal line sequentially selected by the gate driver 12 through thepixel signal line SGL illustrated in FIG. 10. The sub-pixels SPixserving as the display drive targets perform a display of one horizontalline in accordance with the supplied pixel signal Vpix. The driveelectrode driver 14 illustrated in FIG. 1 drives the drive electrode COMwith the drive signal Vcom applied thereto for each drive electrodeblock B, which is illustrated in FIGS. 7 and 9, composed of a certainnumber of drive electrodes COML.

As described above, one horizontal line of the liquid crystal displayunit 20 is sequentially selected in such a manner that the gate driver12 sequentially scans the scan line GCL in a time-division multiplexingmanner. The liquid crystal display unit 20 performs display in units ofone display horizontal line in such a manner that the source driver 13supplies the pixel signal Vpix to the respective sub-pixels SPixincluded in one horizontal line. In the display operation, the driveelectrode driver 14 applies the display drive voltage VcomDC to thedrive electrode block including the drive electrode COML correspondingto the horizontal line.

The drive electrodes COML according to the embodiment function as thedrive electrodes of the liquid crystal display unit 20 and also functionas the drive electrodes of the touch detection device 30. FIG. 12 is aperspective view illustrating an example of the configuration of thedrive electrodes and the touch detection electrodes of the display unitwith a touch detection function according to the first embodiment. Thedrive electrodes COML illustrated in FIG. 12 face the pixel electrodes22 in the direction perpendicular to the surface of the TFT substrate 21as illustrated in FIG. 8. The touch detection device 30 is composed ofthe drive electrodes COML provided on the pixel substrate 2 and thetouch detection electrodes TDL provided on the counter substrate 3. Thetouch detection electrodes TDL are formed in a stripe electrode patternextending in a direction intersecting with the extending direction ofthe electrode patterns of the drive electrodes COML. The touch detectionelectrodes TDL face the drive electrodes COML in the directionperpendicular to the surface of the TFT substrate 21. The electrodepatterns of the touch detection electrodes TDL are coupled to therespective corresponding inputs of the touch detection signal amplifier42 of the touch detection unit 40. Electrostatic capacitances aregenerated between the drive electrodes COML and the touch detectionelectrodes TDL intersecting with each other at respective intersectingportions of the electrode patterns of the drive electrodes COML and thetouch detection electrodes TDL. The shape of the touch detectionelectrodes TDL or the drive electrode COML (drive electrode block) isnot limited to the stripe shape. The touch detection electrodes TDL orthe drive electrodes COML (drive electrode blocks) may be formed in acomb-tooth shape. The touch detection electrodes TDL or the driveelectrodes COML (drive electrode blocks) need to be separated from eachother. The shape of the slits separating the drive electrodes COML maybe a straight line or a curve.

In the touch detection device 30 thus configured, the drive electrodedriver 14 drives the drive electrode blocks B illustrated in FIG. 7 suchthat they are line sequentially scanned in a time-division multiplexingmanner when the touch detection operation is performed. As a result,each drive electrode block B (one detection block) composed of the driveelectrodes COML is sequentially selected in a scan direction Scan. Thetouch detection device 30 outputs the touch detection signal Vdet fromthe touch detection electrodes TDL. In this way, the touch detectiondevice 30 performs the touch detection on one detection block.

FIGS. 13 to 15 are schematic diagrams illustrating an operation exampleof the touch detection in the display device with a touch detectionfunction according to the first embodiment. FIG. 16 is a schematicdiagram to explain the display operation and the touch detectionoperation in the display device with a touch detection functionaccording to the first embodiment. In this case, the drive electrodeblocks B composed of the drive electrodes COML illustrated in FIG. 7 are20 drive electrode blocks of B1 to B20. FIGS. 13 to 15 illustrateoperations to apply the touch drive signal VcomAC to the respectivedrive electrode blocks B1 to B20. A drive signal applied block BACindicates the drive electrode block B to which the touch drive signalVcomAC is applied. No voltages are applied to the other drive electrodeblocks B. The other drive electrode blocks B thus are in a state wherepotential is not fixed, called a floating state. The touch drive signalVcomAC is applied to the drive signal applied block BAC and the displaydrive voltage VcomDC may be applied to the other drive electrode blocksB and thus the potential of the other drive electrode blocks B may befixed. The drive electrode driver 14 illustrated in FIG. 1 selects thedrive electrode block B3 out of the drive electrode blocks B, which arethe targets of the touch detection operation, illustrated in FIG. 13 andapplies the touch drive signal VcomAC to the drive electrode block B3.The drive electrode driver 14 then selects the drive electrode block B4out of the drive electrode blocks B illustrated in FIG. 14 and appliesthe touch drive signal VcomAC to the drive electrode block B4. The driveelectrode driver 14 then selects the drive electrode block B5 out of thedrive electrode blocks B illustrated in FIG. 15 and applies the touchdrive signal VcomAC to the drive electrode block B5. In this way, thedrive electrode driver 14 sequentially selects the drive electrode blockB and applies the touch drive signal VcomAC to the selected driveelectrode block B until all of the drive electrode blocks B are scanned.The number of drive electrode blocks B is not limited to 20.

In the touch detection device 30, the drive electrode block Billustrated in FIGS. 13 to 15 corresponds to the drive electrode E1 inthe basic principle of electrostatic capacitance type touch detectiondescribed above. In the touch detection device 30, the touch detectionelectrode TDL (one electrode pattern) corresponds to the touch detectionelectrode E2. The touch detection device 30 detects a touch inaccordance with the basic principle described above. As illustrated inFIG. 12, the electrode patterns intersecting with each other in a gradeseparation manner form electrostatic capacitive touch sensors in amatrix. The touch detection device 30 thus can also detect the positionwhere the contact or approach of an externally approaching object occursby scanning the entire touch detection surface of the touch detectiondevice 30.

As illustrated in FIG. 16, the display unit with a touch detectionfunction 10 performs a display scan Scand in such a manner that the gatedriver 12 line sequentially scans the scan line GCL in a time-divisionmultiplexing manner. As illustrated in FIG. 16, the display unit with atouch detection function 10 performs a touch detection scan Scant inwhich one time scan is completed in a time W1 in such a manner that thedrive electrode driver 14 sequentially selects and drives the driveelectrode block B. As illustrated in FIG. 16, the scan speed of thetouch detection scan Scant is double that of the display scan Scand. Thescan speed of the touch detection set faster than that of the displayenables the display device with a touch detection function 1 to quicklyrespond to the touch of an externally approaching object approachingexternally. As a result, a response performance of the touch detectioncan be improved. The relation between the touch detection scan Scant andthe display scan Scand is not limited to that illustrated in FIG. 16.The scan speed of the touch detection scan Scant may be more than orless than double that of the display scan Scand, for example.

Drive Signal Generator and Drive Electrode Driver

FIG. 17 is a block diagram illustrating a drive signal generator of thedrive electrode driver according to the first embodiment. A drive signalgenerator 14Q includes a high level voltage generator 61, a low levelvoltage generator 62, buffers 63, 64, and 66, and a switching circuit65.

The high level voltage generator 61 generates a high level voltage ofthe touch drive signal VcomAC. The low level voltage generator 62generates a direct-current voltage of the display drive voltage VcomDC.The voltage generated by the low level voltage generator 62 is also usedas a low level voltage of the touch drive signal VcomAC. The buffer 63outputs the voltage supplied from the high level voltage generator 61while performing impedance conversion and supplies the resulting outputto the switching circuit 65. The buffer 64 outputs the voltage suppliedfrom the low level voltage generator 62 while performing impedanceconversion and supplies the resulting output to the switching circuit65. Based on a drive control signal EXVCOM, the switching circuit 65alternately repeats a state with the drive control signal EXVCOM in ahigh level state and another state with the drive control signal EXVCOMin a low level state to generate the touch drive signal VcomAC. When thedrive control signal EXVCOM is at the high level, the switching circuit65 outputs the voltage supplied from the buffer 63, while when the drivecontrol signal EXVCOM is at the low level, the switching circuit 65outputs the voltage supplied from the buffer 64. When the drive controlsignal EXVCOM is at the low level, the switching circuit 65 outputs thevoltage supplied from the buffer 64 as the display drive voltage VcomDCof the direct-current voltage based on the drive control signal EXVCOM.The buffers 63 and 64 are voltage followers, for example. The voltageoutput from the switching circuit 65 is output to an output terminal65E. The buffer 66 outputs the voltage supplied from the low levelvoltage generator 62 while performing impedance conversion and suppliesthe display drive voltage VcomDC of the direct-current voltage to anoutput terminal 66E.

FIG. 18 is a block diagram illustrating the drive electrode driveraccording to the first embodiment. The drive electrode scan units 14Aand 14B each include a scan controller 51, a touch detection scan unit52, and a drive unit 530. The drive unit 530 includes drive sections 53(k) to 53 (k+3). The number of drive sections is the same as the numberof drive electrode blocks B. The scan controller 51 is mounted on theCOG 19. The touch detection scan unit 52 and the drive unit 530 arearranged in the frame located at the periphery of the display area Ad.Hereinafter, any one of the drive sections 53 (k) to 53 (k+3) isdescribed as the drive section 53.

The scan controller 51 supplies a control signal SDCK and a scan startsignal SDST to the touch detection scan unit 52 based on the controlsignal supplied from the control unit 11. The display drive voltageVcomDC output from the drive signal generator 14Q through the outputterminal 66E is supplied to the display wiring LDC. The touch drivesignal VcomAC output from the drive signal generator 14Q through theoutput terminal 65E is supplied to the touch wiring LAC. The scancontroller 51 supplies a drive electrode selecting signal VCOMSEL to thedrive unit 530.

The touch detection scan unit 52 includes drive electrode shiftregisters 52SR and generates scan signals ST (k), ST (k+1), ST (k+2), ST(k+3), and so on. The scan signals ST select the respectivecorresponding drive electrodes COML to which the touch drive signalVcomAC is applied. Specifically, in the touch detection scan unit 52,the scan start signal SDST supplied from the scan controller 51 triggersthe operation of the shift register 52SR. The control signal SDCK istransferred to the respective shift registers 52SR at respectivetransferring stages, and thereby, the respective shift registers 52SR atrespective transferring stages are sequentially selected insynchronization with the control signal SDCK. The selected shiftregisters 52SR send the scan signals, ST (k), ST (k+1), ST (k+2), ST(k+3), and so on, to the respective AND circuits 54 of the drive unit530. In the touch detection scan unit 52, when the selected shiftregister 52SR supplies the high level signal to the (k+2)th drivesection 53 (k+2) as the (k+2)th scan signal ST (k+2), for example, thedrive section 53 (k+2) applies the drive signal VcomAC to the driveelectrodes COML included in the (k+2)th drive electrode block B (k+2).Hereinafter, any one of the scan signals, ST (k), ST (k+1), ST (k+2), ST(k+3), and so on may be referred to as the scan signal ST.

The drive unit 530 is a circuit that applies the display drive voltageVcomDC or the touch drive signal VcomAC supplied from the drive signalgenerator 14Q to the drive electrodes COML based on the scan signal STsupplied from the touch detection scan unit 52 and the drive electrodeselecting signal VCOMSEL supplied from the scan controller 51. The drivesections 53 are provided one each for the output signals of the touchdetection scan unit 52 and supply the drive signal Vcom to therespective corresponding drive electrode blocks B.

Each drive section 53 includes the AND circuit 54 and a selection switchSW for the corresponding drive electrode block B. The selection switchesSW are illustrated as the selection switches SW1, SW2, SW3, and SW4 inFIG. 18. The AND circuit 54 generates and outputs the logical product(AND) of the scan signal ST supplied from the touch detection scan unit52 and the drive electrode selecting signal VCOMSEL supplied from thescan controller 51. The AND circuit 54 has a buffering function toamplify the amplitude to a level capable of controlling the operation ofthe selection switch SW1. In the following description, the selectionswitch SW1 is explained as the representative example of the selectionswitches SW1. The operation of the selection switch SW1 is controlledbased on the signal supplied from the AND circuit 54. The one end of theselection switch SW1 is coupled to the multiple drive electrodes COMLincluded in the drive electrode block B while the other end of theselection switch SW1 is coupled to either the display wiring LDC or thetouch wiring LAC.

The drive section 53 thus configured outputs the touch drive signalVcomAC as the drive signal Vcom when the scan signal ST is at the highlevel and the drive electrode selecting signal VCOMSEL is at the highlevel. When the scan signal ST is at the low level and the driveelectrode selecting signal VCOMSEL is at the low level, the drivesection 53 disconnects the drive electrode block B from the touch wiringLAC and couples drive electrode block B to the display wiring LDC. Thedrive electrode block B selected as the output destination of the touchdrive signal VcomAC is a selected drive electrode block STX. The driveelectrode block B that is not selected as the output destination of thetouch drive signal VcomAC is a not-selected drive electrode block NTX.For example, in FIG. 18, the selected drive electrode block STX is thedrive electrode block B (k+2) when the drive section 53 (k+2) appliesthe drive signal VcomAC to the plurality of drive electrodes COMLincluded in the (k+2)th drive electrode block B (k+2). The driveelectrode blocks B (k), B (k+1), and B (k+3), which are not selected asthe output destinations of the drive signal VcomAC, are the not-selecteddrive electrode blocks NTX.

When the liquid crystal display unit 20 is in the display operation,i.e., the scan signal ST is at the low level, the drive section 53couples the selection switches SW1, SW2, SW3, and SW4 for the respectivecorresponding drive electrode blocks B to the display wiring LDC andoutputs the display drive voltage VcomDC as the drive signal Vcom.

FIG. 19 is a block diagram illustrating the drive unit of the driveelectrode driver according to the first embodiment. FIG. 20 is a blockdiagram illustrating an arrangement example of the selection switches ofthe drive electrode driver according to the first embodiment. In FIGS.19 and 20, the configuration on the first gate driver 12A side isdescribed. The configuration on the second gate driver 12B side is thesame as that on the first gate driver 12A side. In the followingdescription, the selection switch SW1 is explained as the representativeexample. The other selection switches SW2, SW3, and SW4 have the sameconfiguration as the selection switch SW1. The first gate driver 12A(the second gate driver 12B) includes gate shift registers 120SR. Eachgate shift register 120SR starts the operation in response to thevertical start pulse VST, and then is sequentially selected in thevertical scan direction in synchronization with the vertical clock VCK,and outputs a vertical selection pulse to the scan line GCL through abuffer circuit.

The selection switch SW1 includes a plurality of switches COMSW providedfor each drive electrode COML. All of the switches COMSW operate foreach drive electrode COML in response to switch control signals Ssw andSxsw. All of the switches COMSW operate for each drive electrode COMLand select either the connection between the touch wiring LAC and thedrive electrode COML or the connection between the display wiring LDCand the drive electrode COML in a time-division manner.

When one circuit unit composed of a CMOS switch CMOS1 and a CMOS switchCMOS2 is used as the switch COMSW, multiple circuit units are providedfor each drive electrode COML. The CMOS switches CMOS1 and CMOS2 eachinclude a transistor NMOS having an N channel gate and a transistor PMOShaving a P channel gate.

In the CMOS switch CMOS1, a switch signal line GSW is coupled to thegates of the transistor NMOS and the transistor PMOS. In the CMOS switchCMOS2, a switch signal line GxSW is coupled to the gates of thetransistor NMOS and the transistor PMOS. The switch control signal Sswis supplied to the switch signal line GSW and the switch control signalSxsw is supplied to the switch signal line GxSW. High and low levels inpotential of the switch control signals Ssw and Sxsw are reversed toeach other. The CMOS switches CMOS1 and CMOS2 thus can select either theconnection between the touch wiring LAC and the drive electrode COML orthe connection between the display wiring LDC and the drive electrodeCOML in synchronization with each other as the same selection. Asdescribed above, the selection switch SW1 includes the multiple switchesCOMSW for each drive electrode COML and the switches COMSW are coupledin parallel with each other between the touch wiring LAC and the driveelectrode COML. All of the switches COMSW operate in response to theswitch control signals Ssw and Sxsw serving as selection signals foreach drive electrode COML, couple the touch wiring LAC and the driveelectrode COML, and supply the touch drive signal VcomAC to the driveelectrode COML.

The AND circuit 54 includes an inverter 541, a switching circuit 542, abuffer 543, and an inverter 544. The inverter 541 inverts the outputsignal of the drive electrode shift register 52SR at the selectedtransferring stage and outputs the inverted signal to the AND circuit542 when the scan signal ST is at the high level. The AND circuit 542switches the input and output of the inverter 541 in response to thedrive electrode selecting signal VCOMSEL and outputs the switch controlsignal Ssw to the buffer 543. The buffer 543 amplifies the switchcontrol signal Ssw and supplies the amplified switch control signal Sswto the switch signal line GSW. The inverter 544 inverts the switchcontrol signal Ssw output from the buffer 543 and outputs the invertedsignal as the switch control signal Sxsw to supply the signal to theswitch signal line GxSW.

The CMOS switches CMOS1 and CMOS2 are coupled to the touch wiring LACwith a connecting conductor Q3. The CMOS switches CMOS1 and CMOS2 arecoupled to the display wiring LDC with a connecting conductor Q2. TheCMOS switches CMOS1 and CMOS2 are coupled to the drive electrode COMLwith a connecting conductor Q1. The CMOS switches CMOS1 and CMOS2 canselect either the connection between the connecting conductors Q1 and Q2or the connection between the connecting conductors Q3 and Q1 by theswitch control signals Ssw and Sxsw input to the gates of the respectivetransistors NMOS and the respective transistors PMOS.

As illustrated in FIG. 20, the scan line GCL is wired on the same layeras the switch signal lines GSW and GxSW. The scan line GCL is alsocoupled to the gate of the transistor in a similar manner as the switchsignal lines GSW and GxSW. These lines are formed in the same process,which can reduce the manufacturing process. The scan line GCL intersectswith the touch wiring LAC and the display wiring LDC in a gradeseparation manner with an insulation layer interposed therebetween. Theselection switch SW1 is disposed in an area between the scan lines GCL(e.g., the scan lines GCL_(m+1) and GCL_(m+2)) intersecting with thetouch wiring LAC (the display wiring LDC). The distance between the scanlines GCL intersecting with the touch wiring LAC (the display wiringLDC) is the same as that between the adjacent scan lines GCL in thedisplay area Ad.

The TFT substrate 21 corresponds to a specific example of a “substrate”in the disclosure. The pixel electrode 22 corresponds to a specificexample of a “pixel electrode” in the disclosure. The pixel signal lineSGL corresponds to a specific example of a “signal line” in thedisclosure. The drive electrode COML corresponds to a specific exampleof a “drive electrode” in the disclosure. The liquid crystal element LCcorresponds to a specific example of a “display function layer” in thedisclosure. The gate driver 12, the source driver 13, and the driveelectrode driver 14 correspond to specific examples of a “controller” inthe disclosure. The touch detection electrode TDL corresponds to a“touch detection electrode” in the disclosure. The touch wiring LACcorresponds to a specific example of “touch wiring” in the disclosure.

1-1B. Operation and Action

The following describes the operation and action of the display devicewith a touch detection function 1 in the first embodiment. In thefollowing description, the drive signal Vcom serving as the drive signalfor display is described as the display drive voltage VcomDC while thedrive signal Vcom serving as the drive signal for touch detection isdescribed as the touch drive signal VcomAC.

Operation of the Display Device With a Touch Detection Function

The following describes the operation of the display device with a touchdetection function 1. FIG. 21 is an explanatory diagram illustrating anexample of timing waves of the display device with a touch detectionfunction. FIG. 22 is an explanatory diagram illustrating an operationexample of touch detection scan.

In FIG. 21, (A) illustrates a waveform of the touch drive signal VcomAC.In FIG. 21, (B) illustrates a waveform of the display drive signalVcomDC. In FIG. 21, (C) illustrates a waveform of the scan signal Vscan.In FIG. 21, (D) illustrates a waveform of the pixel signal Vpix. In FIG.21, (E) illustrates a waveform of the switch control signal Vsel. InFIG. 21, (F) illustrates a waveform of the pixel signal Vpix. In FIG.21, (G) illustrates a waveform of the drive electrode selecting signalVCOMSEL. In FIG. 21, (H) illustrates a waveform of the display drivesignal Vcom. In FIG. 21, (I) illustrates a waveform of the touchdetection signal Vdet.

In the display device with a touch detection function 1, the touchdetection operation and the display operation are performed in eachhorizontal period (1H). In the display operation, the gate driver 12sequentially applies the scan signal Vscan to the scan line GCL. In thetouch detection operation, the drive electrode driver 14 performs thetouch detection scan by sequentially applying the touch drive signalVcomAC to each drive electrode block B and the touch detection unit 40detects the touch based on the touch detection signal Vdet output fromthe touch detection electrodes TDL. The details are described below.

At timing t0, one horizontal period (1H) starts. At timing t1, the scancontroller 51 of the drive electrode driver 14 changes the voltage ofthe drive electrode selecting signal VCOMSEL from the low level to thehigh level ((G) in FIG. 21). As a result, in the drive electrode driver14, the selection switch SW2 in the (k+1)th drive section 53 (k+1) usedfor touch detection operation selects the connection between theconnecting conductors Q1 and Q2. As a result of the selection, the touchdrive signal VcomAC ((A) in FIG. 21) generated by the drive signalgenerator 14Q is applied to the drive electrodes COML included in the(k+1)th drive electrode block B (k+1) corresponding to the drive section53 (k+1) as the drive signal VcomAC (B (k+1)) through the selectionswitch SW2. In the drive sections 53 excluding the drive section 53(k+1) having the selection switch SW2, the selection switches SW1, SW3,and SW4 each select the connection between the connecting conductors Q3and Q1. As a result, the drive electrodes COML excluding the driveelectrodes COML included in the drive electrode block B (k+1) have thesame potential as the display wiring LDC ((H) in FIG. 21).

At timing t2, the drive signal generator 14Q changes the voltage of thetouch drive signal VcomAC from the low level to the high level ((A) inFIG. 21). Specifically, the drive unit 530 changes the voltage of thetouch drive signal VcomAC from the low level to the high level by theoutput of the switching circuit 65 supplied from the output terminal 65Ein the drive signal generator 14Q. With this change, an AC rectangularwave changing from the low level to the high level is applied to the(k+1)th drive electrode block B (k+1) as the drive signal VcomAC (B(k+1)) ((H) in FIG. 21). The drive signal Vcom (B (k+1)) propagates tothe touch detection electrodes TDL through electrostatic capacitancesand causes the touch detection signal Vdet to change ((I) in FIG. 21).The AC rectangular wave may be a single rectangular wave.

At sampling timing ts, the A/D converter 43 of the touch detection unit40 A/D-converts the output signal of the touch detection signalamplifier 42 to which the touch detection signal Vdet is input ((I) inFIG. 21). The touch detection signal amplifier 42 of the touch detectionunit 40 performs the touch detection based on the A/D conversion resultscollected in a plurality of horizontal periods.

At timing t3, the drive unit 530 changes the voltage of the touch drivesignal VcomAC to the drive signal Vcom for display (the display drivevoltage VcomDC) ((A) in FIG. 21). Specifically, the drive unit 530outputs the output of the buffer 66 from the output terminal 66E in thedrive signal generator 14Q to change the voltage of the touch drivesignal VcomAC to the display drive voltage VcomDC. With this change, thedrive signal Vcom (B (k+1)) applied to the (k+1)th drive electrode blockB (k+1) is changed from the high level to the low level ((H) in FIG. 21)and the touch detection signal Vdet is changed ((I) in FIG. 21).

03475At timing t4, the scan controller 51 of the drive electrode driver14 changes the voltage of the drive electrode selecting signal VCOMSELfrom the high level to the low level ((G) in FIG. 21). As a result, allof the selection switches SW1 to SW4 select the connection between theconnecting conductors Q2 and Q1. The display drive voltage VcomDC ((B)in FIG. 21) generated by the drive signal generator 14Q is applied tothe drive electrodes COML included in the respective corresponding driveelectrode blocks B through all of the selection switches SW1 to SW4 ((H)in FIG. 21).

At timing t5, the gate driver 12 applies the scan signal Vscan to them-th scan line GCL (m) used for the display operation and the voltage ofthe scan line GCL (m) is changed from the low level to the high level((c) in FIG. 21). The source driver 13 and the source selector 13S applythe pixel signal Vpix to the pixel signal line SGL ((F) in FIG. 21) suchthat the pixels Pix included in one horizontal line relating to the m-thscan line GCL (m) perform display.

Specifically, at timing t5, the gate driver 12 selects one horizontalline used for the display operation by changing the voltage of the scansignal Vscan (m) from the low level to the high level. The source driver13 supplies the pixel voltage VR for the sub-pixel SPix of red to thesource selector 13S as the image signal Vsig ((D) in FIG. 21), generatesthe switch control signal VselR, which keeps the high level during aperiod of supplying the pixel voltage VR, and supplies the generatedswitch control signal VselR to the source selector 13S ((E) in FIG. 21).The source selector 13S separates the pixel voltage VR supplied from thesource driver 13 from the image signal Vsig by turning on the switch SWRduring a period (a writing period PW) in which the voltage of the switchcontrol signal VselR is at the high level, and supplies the separatedpixel voltage VR to the sub-pixels SPix of red in the horizontal line asthe pixel signal VpixR through the pixel signal line SGL ((F) in FIG.21). After the switch SWR is turned off, the pixel signal line SGL is inthe floating state. As a result, the voltage of the pixel signal lineSGL is maintained ((F) in FIG. 21). Likewise, the source driver 13supplies the pixel voltage VG for the sub-pixels SPix of green to thesource selector 13S together with the corresponding switch controlsignal VselG ((D) and (E) in FIG. 21). The source selector 13S separatesthe pixel voltage VG from the image signal Vsig based on the switchcontrol signal VselG, and supplies the pixel voltage VG to thesub-pixels SPix of green in the horizontal line as the pixel signalVpixG through the pixel signal line SGL ((F) in FIG. 21). Likewise, thesource driver 13 supplies the pixel voltage VB for the sub-pixels SPixof blue to the source selector 13S together with the correspondingswitch control signal VselB ((D) and (E) in FIG. 21). The sourceselector 13S separates the pixel voltage VB from the image signal Vsigbased on the switch control signal VselB, and supplies the pixel voltageVB to the sub-pixels SPix of blue in the horizontal line as the pixelsignal VpixB through the pixel signal line SGL ((F) in FIG. 21).

At timing t6, the gate driver 12 changes the voltage of the scan signalVscan (m) of the m-th scan line GCL from the high level to the low level((C) in FIG. 21). As a result, the sub-pixels SPix on the horizontalline used for the display operation are electrically isolated from thepixel signal line SGL.

At timing t10, the horizontal period ends and a new horizontal periodstarts.

With the repetition of the operation described above, in the displaydevice with a touch detection function 1, the display operation isperformed on the entire display screen by the line sequential scanningand touch detection operation is performed on the entire touch detectionsurface by scanning each drive electrode block B in the followingmanner.

(A) in FIG. 22 illustrates a waveform of the touch drive signal VcomAC.(B) in FIG. 22 illustrates a waveform of the display drive signalVcomDC. (C) in FIG. 22 illustrates a waveform of the drive electrodeselecting signal VCOMSEL. (D) in FIG. 22 illustrates a waveform of thescan signal ST. (E) in FIG. 22 illustrates a waveform of the displaydrive signal Vcom. (F) in FIG. 22 illustrates a waveform of the touchdetection signal Vdet.

The drive electrode driver 14 performs the touch detection scan bysequentially applying the touch drive signal VcomAC to the respectivecorresponding drive electrode blocks B ((E) in FIG. 22) based on thescan signal ST ((D) in FIG. 22) generated by the touch detection scanunit 52. In the touch detection scan, the drive electrode driver 14applies the touch drive signal VcomAC to the respective drive electrodeblocks B in a certain plurality of horizontal periods ((E)in FIG. 22).The touch detection unit 40 samples the touch detection signal Vdetbased on the touch drive signal VcomAC in each horizontal period 1H.After the touch detection unit 40 completes the sampling in the lasthorizontal period of the plurality of horizontal periods, the signalprocessor 44 detects whether a touch exists in areas corresponding tothe respective drive electrode blocks B based on the plurality ofsampling results. The touch detection thus performed based on theplurality of sampling results enables the sampling results to bestatistically analyzed, thereby making it possible to reduce thedeterioration of a signal-to-noise (S/N) ratio due to variations insampling results. As a result, touch detection accuracy can beincreased. The touch drive signal VcomAC illustrated in FIG. 21 or 22has a single rectangular wave for schematically explaining the signal.The touch drive signal VcomAC may be composed of a plurality of waves asillustrated in FIG. 6. The display device with a touch detectionfunction 1 according to the first embodiment separates the touchdetection operation (touch detection operation period) and thedisplaying operation (displaying period) and supplies the drive signalVcom (the display drive voltage VcomDC and the drive signal VcomAC) tothe drive electrodes COML in a time-division manner. As described above,the display device with a touch detection function 1 according to thefirst embodiment may separate the touch detection operation (touchdetection operation period) and the displaying operation (displayingperiod) and supply the drive signal Vcom (the display drive voltageVcomDC and the drive signal VcomAC) to the drive electrodes COML in atime-division manner, in one display horizontal period. The displaydevice with a touch detection function 1 according to the firstembodiment may separate a plurality of times of touch detectionoperation (touch detection operation periods) and a plurality of timesof displaying operation (displaying periods) and supply the drive signalVcom (the display drive voltage VcomDC and the drive signal VcomAC) tothe drive electrodes COML in a time-division manner, in one displayhorizontal period. The display device with a touch detection function 1according to the first embodiment may separate the touch detectionoperation (touch detection operation period) and the displayingoperation (displaying period) and process the display operationcorresponding to a plurality of horizontal periods in one displayperiod.

1-1C. Advantages

As described above, in display device with a touch detection function 1according to the first embodiment, the display wiring LDC supplying thedisplay drive voltage VcomDC to the drive electrodes COML and the touchwiring LAC supplying the touch drive signal VcomAC to the driveelectrodes COML are routed in the frame areas. For example, in theliquid crystal display device using a liquid crystal of a lateralelectric field mode such as FFS, the display function layer tends tooperate stably when the display wiring LDC is arranged close to thepixels corresponding to the color areas 32R, 32G, and 32B. Thus, theselection switches SW1 to SW4 are arranged between the touch wiring LACand the display wiring LDC. The selection switches SW1 to SW4 eachincludes the connecting conductors Q1, Q2, and Q3 as through holes indifferent layers. The selection switch SW1 (as the representativeexample of the selection switches SW1, SW2, SW3, and SW4) includes themultiple switches COMSW for each drive electrode COML. All of theswitches COMSW operate in response to the switch control signals Ssw andSxsw to couple the touch wiring LAC to the drive electrode COML andapply the touch drive signal VcomAC to the drive electrode COML. Thisconfiguration can reduce the interconnection resistance in the selectionswitch SW1 by increasing the number of connecting conductors Q1, Q2, andQ3, which supply power.

The touch wiring LAC has a predetermined interconnection resistancecomponent of the switch SW1 and a parasitic capacitance between itselfand the drive electrodes COML included in the drive electrode block B towhich the drive signal VcomAC is applied through the touch wiring LAC.Thus, the transition time of the pulse of the drive signal VcomAC mayget longer at the drive electrode block B disposed away from the COG 19(drive signal generator). In the selection switch SW1 according to thefirst embodiment, the multiple CMOS switches CMOS1 and CMOS2 of theswitch COMSW are provided in parallel with each other between the touchwiring LAC and the drive electrode COML, for each drive electrode COML.All of the CMOS switches CMOS1 and CMOS2 operate in response to theswitch control signals serving as the selection signals to couple thetouch wiring LAC to the drive electrode COML, and can supply the touchdrive signal VcomAC to the drive electrode COML. This configurationenables the display device with a touch detection function 1 accordingto the first embodiment to reduce the interconnection resistance of theswitch SW1. As a result, the display device with a touch detectionfunction 1 according to the first embodiment can reduce the potentialitythat the transition time of the pulse of the drive signal VcomAC getslonger at the drive electrode block B disposed near the end of the touchwiring LAC.

1-2. Second Embodiment

The following describes the display device with a touch detectionfunction 1 according to a second embodiment. FIG. 23 is a schematicdiagram illustrating an example of the controller of the display devicewith a touch detection function according to the second embodiment. FIG.24 is a block diagram illustrating the drive unit of the drive electrodedriver according to the second embodiment. FIG. 25 is a block diagramillustrating an arrangement example of the selection switches of thedrive electrode driver according to the second embodiment. The sameconstituent elements as the first embodiment are labeled with the samereference numerals, and the duplicated descriptions thereof are omitted.In FIGS. 25 and 26, the configuration on the first gate driver 12A sideis described. The configuration on the second gate driver 12B side isthe same as that on the first gate driver 12A side.

As illustrated in FIG. 23, the pixel substrate 2 includes, on thesurface of the TFT substrate 21 of a transparent insulation substrate(e.g., a glass substrate), the display area Ad in which a large numberof pixels including liquid crystal cells are arranged in a matrix (rowsand columns), the source driver (horizontal drive circuit) 13, and thegate drivers (vertical drive circuits) 12A and 12B. The gate drivers(vertical drive circuits) 12A and 12B are arranged as the first gatedriver 12A and the second gate driver 12B with the display area Adinterposed therebetween. The first gate driver 12A and the second gatedriver 12B alternately apply the vertical scan pulse to the scan lineGCL in the scan direction to select the respective sub-pixels SPix inthe display area Ad row by row. The first gate driver 12A and the secondgate driver 12B are arranged at the ends of the scan line GSL in thelongitudinal direction and alternately apply the vertical scan pulse toevery other scan line GCL to select the respective pixels in the displayarea Ad row by row.

As illustrated in FIG. 24, the number of scan lines GCL reaching thefirst gate driver 12A or the second gate driver 12B after passing overthe display area Ad and through the frame Gd is smaller than that in thefirst embodiment. As a result, the odd-number-th scan lines GCL coupledto the first gate driver 12A pass through the frame Gd and into thedisplay area Ad and the even-number-th scan lines GCL coupled to thesecond gate driver 12B pass through the frame Gd and into the displayarea Ad. As a result, the CMOS switch CMOS1 of the selection switch SW1is disposed in an area between the scan lines GCL (e.g., the scan linesGCL_(m+1) and GCL_(m+3)) intersecting with the touch wiring LAC (thedisplay wiring LDC) in a grade separation manner. For example, the scanlines GCL coupled to the first gate driver 12A (e.g., the scan linesGCL_(m+1) and GCL_(m+3)) intersect with the touch wiring LAC on thefirst gate driver 12A side in a grade separation manner but do notintersect with the touch wiring LAC on the second gate driver 12B sidein a grade separation manner. The scan lines GCL coupled to the secondgate driver 12B (e.g., the scan lines GCL_(m+2) and GCL_(m+4)) intersectwith the touch wiring LAC on the second gate driver 12B side in a gradeseparation manner but do not intersect with the touch wiring LAC on thefirst gate driver 12A side in a grade separation manner. The distancebetween the scan lines GCL intersecting with the touch wiring LAC (thedisplay wiring LDC) in a grade separation manner is larger than thatbetween the adjacent scan lines GCL in the display area Ad. In otherwords, the distance between the scan lines GCL in the frame Gd is largerthan that between the adjacent scan lines GCL in the display area Ad.With an increase in distance between the scan lines GCL in the frame Gd,an area increases in which the selection switch SW1 (the CMOS switchesCMOS1 and CMOS2) can be disposed. The increase in number or in area ofconnecting conductors Q1, Q2, and Q3 can reduce the interconnectionresistance of the selection switch SW1.

The selection switch SW1 is disposed not only in the frame area Gd onthe first gate driver 12A side but also in the frame area Gd on thesecond gate driver 12B side. The selection switch SW1 disposed in theframe area Gd on the second gate driver 12B side can select theconnection between the touch wiring LAC disposed on the second gatedriver 12B side and the electrodes COML or the connection between thedisplay wiring LDC disposed on the second gate driver 12B side and theelectrodes COML. In this case, the selection switch on the first gatedriver 12A side and the selection switch on the second gate driver 12Bside that are coupled to the same drive electrode COML select the sametype of the wiring (the touch wiring LAC or the display wiring LDC). Forexample, the selection switch SW1 on the second gate driver 12B sidecoupled to the same drive electrode COML as the selection switch SW1 onthe first gate driver 12A side selects the connection between the touchwiring LAC and the drive electrode COML when the selection switch SW1 onthe first gate driver 12A side selects the connection between the touchwiring LAC and the drive electrode COML. The selection switch SW1 on thesecond gate driver 12B side coupled to the same drive electrode COML asthe selection switch SW1 on the first gate driver 12A side selects theconnection between the display wiring LDC and the drive electrode COMLwhen the selection switch SW1 on the first gate driver 12A side selectsthe connection between the display wiring LDC and the drive electrodeCOML.

Advantages

The reduction in pixel pitches with an increase in accuracy may increasethe interconnection resistance of the selection switch SW1 when theselection switch SW1 is disposed between the scan lines GCL the distanceof which corresponds to the pitch between the sub-pixels SPix asdescribed in the first embodiment. In contrast, the display device witha touch detection function 1 according to the second embodiment can keepthe interconnection resistance of the selection switch SW1 low even ifthe pixel pitches are reduced with an increase in accuracy because theselection switch SW1 can be disposed between the scan lines GCL thedistance of which is larger than the pitch between the sub-pixels SPix.In addition, the interconnection resistance in the selection switch SW1can be reduced by increasing the number of connecting conductors Q1, Q2,and Q3, which supply power.

The touch wiring LAC has a predetermined interconnection resistancecomponent of the switch SW1 and a parasitic capacitance between itselfand the drive electrodes COML included in the drive electrode block B towhich the drive signal VcomAC is applied through the touch wiring LAC.Thus, the transition time of the pulse of the drive signal VcomAC mayget longer at the drive electrode block B disposed away from the COG 19(drive signal generator). The multiple CMOS switches CMOS1 and CMOS2 ofthe switch COMSW of the selection switch SW1 (as a representativeexample of the switches SW1, SW2, SW3, and SW4) according to the secondembodiment are provided in parallel with each other between the touchwiring LAC and the drive electrode COML, for each drive electrode COML.All of the CMOS switches CMOS1 and CMOS2 operate in response to theswitch control signals serving as the selection signals to couple thetouch wiring LAC to the drive electrodes COML, and can supply the touchdrive signal VcomAC to the drive electrode COML. The display device witha touch detection function 1 according to the second embodiment reducesthe potentiality that the transition time of the pulse of the drivesignal VcomAC gets longer at the drive electrode block B disposed nearthe end of the touch wiring LAC because the interconnection resistanceof the selection switch SW1 is reduced.

The selection switch SW1 according to the second embodiment can bereduced in size in a direction in parallel with the scan line and can beincreased in size in a direction perpendicular to the scan line. As aresult, in the display device with a touch detection function 1according to the second embodiment, the width Gdv in the frame Gdillustrated in FIG. 7 can be reduced. The width Gdv is the width of thearea in parallel with the scan line in the frame Gd and in which areathe selection switch SW1 is disposed.

1-3. Third Embodiment

The following describes the display device with a touch detectionfunction 1 according to a third embodiment. FIG. 26 is a block diagramillustrating the drive unit of the drive electrode driver according tothe third embodiment. FIG. 27 is a block diagram illustrating anarrangement example of the selection switches of the drive electrodedriver according to the third embodiment. The same constituent elementsas the first and the second embodiments are labeled with the samereference numerals, and the duplicated descriptions thereof are omitted.In FIGS. 25 and 26, the drive electrode driver on the first gate driver12A side is described. The configuration on the second gate driver 12Bside is the same as that on the first gate driver 12A side.

As illustrated in FIG. 23, the pixel substrate 2 includes, on thesurface of the TFT substrate 21 of a transparent insulation substrate(e.g., a glass substrate), the display area Ad in which a large numberof pixels including liquid crystal cells are arranged in a matrix (rowsand columns), the source driver (horizontal drive circuit) 13, and thegate drivers (vertical drive circuits) 12A and 12B, also in the thirdembodiment. The gate drivers (vertical drive circuits) 12A and 12B arearranged as the first gate driver 12A and the second gate driver 12Bwith the display area Ad interposed therebetween. The first gate driver12A and the second gate driver 12B alternately apply the vertical scanpulse to the scan line in the scan direction to select the respectivesub-pixels SPix in the display area Ad row by row.

As illustrated in FIG. 26, the number of scan lines GCL reaching thefirst gate driver 12A or the second gate driver 12B after passing overthe display area Ad and through the frame Gd is smaller than that in thefirst embodiment. The plurality of scan lines are arranged between theadjacent switches COMSW. For example, the scan lines GCL_(m+2) andGCL_(m+4) are arranged between the adjacent switches COMSW, and the scanlines GCL_(m+6) and GCL_(m+8) are arranged between the adjacent switchesCOMSW. The arrangement pitch of the scan lines arranged in such a mannercoincides with the arrangement pitch of the gate shift registers 120SRof the first gate driver 12A (the second gate driver 12B). The gateshift registers 120SR control two scan lines GCL as a pair. In theselection switch SW1, the space for the switch COMSW corresponds to fourarrangement pitches of the sub-pixels SPix and the repeating pitch ofthe switch COMSW corresponds to eight arrangement pitches of thesub-pixels SPix. As a result, the even-number-th scan lines GCL coupledto the first gate driver 12A pass through the frame Gd and into thedisplay area Ad and the odd-number-th scan lines GCL coupled to thesecond gate driver 12B pass through the frame Gd and into the displayarea Ad. As a result, the CMOS switch CMOS2 is disposed in an areabetween the scan lines GCL that intersect with the touch wiring LAC (thedisplay wiring LDC) in a grade separation manner and adjacent to theCMOS switches CMOS1 and CMOS2 (e.g., between the scan lines GCL_(m+4)and GCL_(m+6)). For example, the scan lines GCL (e.g., the scan linesGCL_(m+2), GCL_(m+4), GCL_(m+6), and GCL_(m+8)) coupled to the firstgate driver 12A intersect with the touch wiring LAC on the first gatedriver 12A side in a grade separation manner but do not intersect withthe touch wiring LAC on the second gate driver 12B side in a gradeseparation manner. The scan lines GCL coupled to the second gate driver12B (e.g., the scan lines GCL_(m+1), GCL_(m+3), GCL_(m+5), andGCL_(m+7)) intersect with the touch wiring LAC on the second gate driver12B side in a grade separation manner but do not intersect with thetouch wiring LAC on the first gate driver 12A side in a grade separationmanner. The distance between the scan lines GCL intersecting with thetouch wiring LAC (the display wiring LDC) in a grade separation manneris larger than that between the adjacent scan lines GCL in the displayarea Ad. With an increase in distance between the scan lines GCL in theframe Gd, an area increases in which the selection switch SW1 (the CMOSswitch CMOS2) can be disposed. The increase in number or in area ofconnecting conductors Q1, Q2, and Q3 can reduce the interconnectionresistance of the selection switch SW1, for example.

The selection switch SW1 is disposed not only in the frame area Gd onthe first gate driver 12A side but also in the frame area Gd on thesecond gate driver 12B side. The selection switch SW1 disposed in theframe area Gd on the second gate driver 12B side can select theconnection between the touch wiring LAC disposed on the second gatedriver 12B side and the electrodes COML or the connection between thedisplay wiring LDC disposed on the second gate driver 12B side and theelectrodes COML. In this case, the selection switch on the first gatedriver 12A side and the selection switch on the second gate driver 12Bside that are coupled to the same drive electrode COML select the sametype of the wiring (the touch wiring LAC or the display wiring LDC). Forexample, the selection switch SW1 on the second gate driver 12B sidecoupled to the same drive electrode COML as the selection switch SW1 onthe first gate driver 12A side selects the connection between the touchwiring LAC and the drive electrode COML when the selection switch SW1 onthe first gate driver 12A side selects the connection between the touchwiring LAC and the drive electrode COML. The selection switch SW1 on thesecond gate driver 12B side coupled to the same drive electrode COML asthe selection switch SW1 on the first gate driver 12A side selects theconnection between the display wiring LDC and the drive electrode COMLwhen the selection switch SW1 on the first gate driver 12A side selectsthe connection between the display wiring LDC and the drive electrodeCOML.

Advantages

The reduction in pixel pitches with an increase in accuracy may increasethe interconnection resistance of the selection switch SW1 when theselection switch SW1 is disposed in the scan lines GCL the distance ofwhich corresponds to the pitch between the sub-pixels SPix as describedin the first embodiment. In contrast, display device with a touchdetection function 1 according to the third embodiment can keep theinterconnection resistance of the selection switch SW1 low even if thepixel pitches are reduced with an increase in accuracy because theselection switch SW1 can be disposed between the scan lines GCL thedistance of which is larger than the pitch between the sub-pixels SPix.In addition, the interconnection resistance in the selection switch SW1can be reduced by increasing the number of connecting conductors Q1, Q2,and Q3, which supply power.

The touch wiring LAC has a predetermined interconnection resistancecomponent of the switch SW1 and a parasitic capacitance between itselfand the drive electrodes COML included in the drive electrode block B towhich the drive signal VcomAC is applied through the touch wiring LAC.Thus, the transition time of the pulse of the drive signal VcomAC mayget longer at the drive electrode block B disposed away from the COG 19(drive signal generator). The multiple CMOS switches CMOS1 and CMOS2 ofthe switch COMSW of the selection switch SW1 (as a representativeexample of the switches Sw1, SW2, SW3, and SW4) according to the thirdembodiment are provided in parallel with each other between the touchwiring LAC and the drive electrode COML, for each drive electrode COML.All of the CMOS switches CMOS1 and CMOS2 operate in response to theswitch control signals serving as the selection signals to couple thetouch wiring LAC to the corresponding drive electrode COML, and cansupply the touch drive signal VcomAC to the drive electrode COML. Thedisplay device with a touch detection function 1 according to the thirdembodiment reduces the potentiality that the transition time of thepulse of the drive signal VcomAC gets longer at the drive electrodeblock B disposed near the end of the touch wiring LAC because theinterconnection resistance of the selection switch SW1 is reduced.

The selection switch SW1 according to the third embodiment can bereduced in size in a direction in parallel with the scan line and can beincreased in size in a direction perpendicular to the scan line. As aresult, in the display device with a touch detection function 1according to the third embodiment, the width Gdv in the frame Gdillustrated in FIG. 7 can be reduced. The width Gdv is the width of thearea in parallel with the scan line in the frame Gd and in which areathe selection switch SW1 is disposed.

The present disclosure is not limited to the embodiments and themodifications described above and can be modified in various ways.

The display device with a touch detection function 1 according to theembodiments and the modifications described above can include thedisplay unit with a touch detection function 10 that is configured byintegrating the touch detection device 30 and the liquid crystal displayunit 20 using a liquid crystal of various modes such as FFS and IPS.FIG. 28 is a cross-sectional diagram illustrating a schematiccross-sectional structure of the display unit with a touch detectionfunction according to a modification. The display unit with a touchdetection function 10 according to the modification illustrated in FIG.28 may be configured by integrating the touch detection device and aliquid crystal of various modes such as twisted nematic (TN), verticalalignment (VA), and electrically controlled birefringence (ECB) modes.

As illustrated in FIG. 28, the touch wiring LAC and the display wiringLDC may be provided to the counter substrate 3 when the drive electrodesCOML are provided to the counter substrate 3. With this configuration,the distance between the drive electrodes COML and the touch wiring LAC(the display wiring LDC) is shortened. The scan lines GCL provided tothe TFT substrate 21 intersect with the touch wiring LAC and the displaywiring LDC in a grade separation manner in the same manner as the first,the second, and the third embodiments. As a result, the touch wiring LACis provided in the frame area Gd located outside the display area Ad inthe direction perpendicular to the TFT substrate 21.

In the embodiments described above, the display unit with a touchdetection function 10 is an in-cell type, in which the liquid crystaldisplay unit 20 and the electrostatic capacitance touch detection device30 are integrated. The display unit with a touch detection function 10however is not limited to this type. The display unit with a touchdetection function 10 may be an on-cell type in which the electrostaticcapacitance touch detection device 30 is attached on the liquid crystaldisplay unit 20. In the on-cell type, the drive electrodes COML of thepixel substrate 2 illustrated in FIG. 8 operates as first driveelectrodes COML, and second drive electrodes COML are provided on thesurface of the glass substrate 31, and the first and the second driveelectrodes are electrically coupled. In this case, the use of theconfiguration described above enables the touch detection to beperformed without being influenced by the external noises and the noisespropagated from the liquid crystal display device (corresponding to theinternal noises in the embodiments).

2. Application Examples

The following describes application examples of the display device witha touch detection function 1 described in the embodiments and themodification with reference to FIGS. 29 to 41. FIGS. 29 to 41 areschematic diagrams illustrating examples of an electronic apparatus towhich the display device with a touch detection function according tothe embodiments is applied. The display device with a touch detectionfunction 1 according to the first, the second, and the third embodimentscan be applied to all the fields of electronic apparatuses such astelevision apparatuses, digital cameras, notebook personal computers,portable terminals such as portable phones, and video cameras. In otherwords, the display device with a touch detection function 1 according tothe first, the second, and the third embodiments and the modificationcan be applied to all the fields of electronic apparatuses displaying anexternally input video signal or an internally generated image signal asan image or a video.

2-1. Application Example 1

The electronic apparatus illustrated in FIG. 29 is a televisionapparatus to which the display device with a touch detection function 1according to the first, the second, and the third embodiments and themodification is applied. The television apparatus includes a videodisplay screen unit 510 having a front panel 511 and a filter glass 512,for example. The video display screen unit 510 is the display devicewith a touch detection function according to the first, the second, andthe third embodiments and the modification.

2-2. Application Example 2

The electronic apparatus illustrated in FIGS. 30 and 31 is a digitalcamera to which the display device with a touch detection function 1according to the first, the second, and the third embodiments and themodification is applied. The digital camera includes a light-emittingunit 521 for flash, a display unit 522, a menu switch 523, and a shutterbutton 524, for example. The display unit 522 is the display device witha touch detection function according to the first, the second, and thethird embodiments and the modification.

2-3. Application Example 3

FIG. 32 illustrates an outer appearance of a video camera to which thedisplay device with a touch detection function 1 according to the first,the second, and the third embodiments and the modification is applied.The video camera includes a main body 531, a subject photographing lens532 disposed on the front side surface of the main body 531, aphotographing start/stop switch 533, and a display unit 534, forexample. The display unit 534 is the display device with a touchdetection function according to the first, the second, and the thirdembodiments and the modification.

2-4. Application Example 4

The electronic apparatus illustrated in FIG. 33 is a notebook personalcomputer to which the display device with a touch detection function 1according to the first, the second, and the third embodiments and themodification is applied. The notebook personal computer includes a mainbody 541, a keyboard 542 for input operation of characters, and adisplay unit 543 displaying an image, for example. The display unit 543is the display device with a touch detection function according to thefirst, the second, and the third embodiments and the modification.

2-5. Application Example 5

The electronic apparatus illustrated in FIGS. 34 to 40 is a portablephone to which the display device with a touch detection function 1according to the first, the second, and the third embodiments and themodification is applied. The portable phone includes an upper case 551and a lower case 552 that are coupled with a joint (hinge) 553, adisplay 554, a sub display 555, a picture light 556, and a camera 557,for example. The display 554 or the sub display 555 is the displaydevice with a touch detection function according to the first, thesecond, and the third embodiments and the modification.

2-6. Application Example 6

The electronic apparatus illustrated in FIG. 41 is an informationportable terminal that operates as a portable computer, amulti-functional portable phone, a portable computer having a voicecommunication function, or a portable computer having a communicationfunction, and is called a smartphone or a tablet terminal. Theinformation portable terminal includes a housing 561 having a displayunit 562 on the surface thereof, for example. The display unit 562 isthe display device with a touch detection function 1 according to thefirst, the second, and the third embodiments and the modification.

3. Aspects of the Present Disclosure

The present disclosure includes the following aspects.

-   (1) A display device with a touch detection function, comprising:    -   a display area including a plurality of pixel electrodes        arranged in a matrix on a substrate;    -   a plurality of drive electrodes that are disposed to face the        plurality of pixel electrodes;    -   a display function layer that has an image display function to        display an image in the display area;    -   a controller that performs image display control to fulfill the        image display function of the display function layer by applying        a display drive voltage between the plurality of pixel        electrodes and the plurality of drive electrodes based on an        image signal;    -   a plurality of touch detection electrodes that face the        plurality of drive electrodes, and form an electrostatic        capacitance between the plurality of drive electrodes and the        plurality of touch detection electrodes;    -   a touch detection unit that detects a position of an approaching        object based on a detection signal from the plurality of touch        detection electrodes;    -   touch wiring that is routed in a frame area located outside the        display area and supplies a touch drive signal to the plurality        of drive electrodes; and    -   a plurality of switch groups that are provided for each of the        plurality of drive electrodes, each of the plurality of switch        groups having a plurality of selection switches that operate        based on a selection signal from the controller, wherein    -   the plurality of switch groups select a drive electrode to be        coupled to the touch wiring from the plurality of drive        electrodes based on a selection signal from the controller, and    -   the plurality of selection switches for each of the plurality of        switch groups are coupled in parallel with each other between a        corresponding drive electrode and the touch wiring, and for each        of the plurality of drive electrodes, all of the plurality of        selection switches operate in accordance with the selection        signal, couple the corresponding drive electrodes and the touch        wiring, and apply the touch drive signal to the corresponding        drive electrodes.-   (2) The display device with a touch detection function according to    (1), wherein    -   the controller includes a vertical drive circuit,    -   the vertical drive circuit is coupled to a plurality of scan        lines that select pixels in a row unit, and    -   the plurality of scan lines intersect with the touch wiring in a        grade separation manner and the selection switches are arranged        in an area between the adjacent scan lines.-   (3) The display device with a touch detection function according to    (2), wherein    -   the vertical drive circuit includes a first vertical drive        circuit and a second vertical drive circuit,    -   the first and the second vertical drive circuits are disposed at        ends of the plurality of scan lines in a longitudinal direction        of the plurality of scan lines and select the respective pixels        in the display area row by row by alternately applying a        vertical scan pulse to every other scan line, and    -   a distance between the scan lines intersecting with the touch        wiring in a grade separation manner is larger than a distance        between the adjacent scan lines in the display area.-   (4) The display device with a touch detection function according to    (2), wherein    -   the vertical drive circuit includes a first vertical circuit and        a second vertical circuit,    -   the first and the second vertical drive circuits are disposed        with the plurality of scan lines interposed therebetween in an        extending direction of the plurality of scan lines, and select        the respective pixels in the display area row by row by        alternately applying a vertical scan pulse to the scan lines in        a scan direction,    -   the scan lines are arranged between the adjacent selection        switches, and    -   a distance between the scan lines intersecting with the touch        wiring in a grade separation manner and being adjacent to the        selection switch is larger than a distance between the adjacent        scan lines in the display area.-   (5) The display device with a touch detection function according to    (3), wherein    -   the touch wiring includes first touch wiring on the first        vertical drive circuit side and second touch wiring on the        second vertical drive circuit side,    -   the scan lines coupled to the first vertical drive circuit        intersect with the first touch wiring on the first vertical        drive circuit side in a grade separation manner and do not        intersect with the second touch wiring on the second vertical        drive circuit side in a grade separation manner, and    -   the scan lines coupled to the second vertical drive circuit        intersect with the second touch wiring on the second vertical        drive circuit side in a grade separation manner and do not        intersect with the first touch wiring on the first vertical        drive circuit side in a grade separation manner.-   (6) The display device with a touch detection function according to    (4), wherein    -   the touch wiring includes first touch wiring on the first        vertical drive circuit side and second touch wiring on the        second vertical drive circuit side,    -   the scan lines coupled to the first vertical drive circuit        intersect with the first touch wiring on the first vertical        drive circuit side in a grade separation manner and do not        intersect with the second touch wiring on the second vertical        drive circuit side in a grade separation manner, and    -   the scan lines coupled to the second vertical drive circuit        intersect with the second touch wiring on the second vertical        drive circuit side in a grade separation manner and do not        intersect with the first touch wiring on the first vertical        drive circuit side in a grade separation manner.-   (7) The display device with a touch detection function according to    (2), wherein a distance between the scan lines intersecting with the    touch wiring in a grade separation manner is a distance between the    adjacent scan lines in the display area.-   (8) The display device with a touch detection function according to    (1), further comprising:    -   display wiring that supplies the display drive voltage, wherein    -   the display wiring is disposed closer to the display area than        the touch wiring.-   (9) The display device with a touch detection function according to    (8), wherein the plurality of selection switches select either a    connection between the plurality of drive electrodes and the display    wiring or a connection between the plurality of drive electrodes and    the touch wiring in a time-division manner.-   (10) An electronic apparatus having a display device with a touch    detection function capable of detecting an externally approaching    object, the display device with a touch detection function    comprising:    -   a display area including a plurality of pixel electrodes        arranged in a matrix on a substrate;    -   a plurality of drive electrodes that are disposed to face the        plurality of pixel electrodes    -   a display function layer that has an image display function to        display an image in the display area;    -   a controller that performs image display control to fulfill the        image display function of the display function layer by applying        a display drive voltage between the plurality of pixel        electrodes and the plurality of drive electrodes based on an        image signal;    -   a plurality of touch detection electrodes that face the        plurality of drive electrodes, and form an electrostatic        capacitance between the plurality of drive electrodes and the        plurality of touch detection electrodes;    -   a touch detection unit that detects a position of an approaching        object based on a detection signal from the plurality of touch        detection electrodes;    -   touch wiring that is routed in a frame area located outside the        display area and supplies a touch drive signal to the plurality        of drive electrodes; and    -   a plurality of switch groups that are provided for each of the        plurality of drive electrodes, each of the plurality of switch        groups having a plurality of selection switches that operate        based on a selection signal from the controller, wherein    -   the plurality of switch groups select a drive electrode to be        coupled to the touch wiring from the plurality of drive        electrodes based on a selection signal from the controller, and    -   the plurality of selection switches for each of the plurality of        switch groups are coupled in parallel with each other between a        corresponding drive electrode and the touch wiring, and for each        of the plurality of drive electrodes, all of the plurality of        selection switches operate in accordance with the selection        signal, couple the corresponding drive electrodes and the touch        wiring, and apply the touch drive signal to the corresponding        drive electrodes.

The display device with a touch detection function and the electronicapparatus according to the disclosure can reduce the interconnectionresistances of the selection switches that select the drive electrode towhich the drive signal is applied and also reduce the frame in size.

Examples of the electronic apparatus include, but are not limited to, atelevision device, a digital camera, a personal computer, a videocamera, and a portable terminal device such as a portable phone.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention is claimed as follows:
 1. A display device with a touchdetection function, comprising: a display area including a plurality ofpixels arranged in a matrix on a substrate; a plurality of driveelectrodes disposed to face at least one of the pixels; a displayfunction layer that has an image display function to display an image inthe display area; touch wiring that is routed in a frame area locatedoutside the display area and supplies an alternating current touch drivesignal to the drive electrodes; display wiring that supplies the displaydrive voltage; and a plurality of switches conducting between at leastone of the drive electrodes and the touch wiring in a touch detectionperiod, and conducting between at least one of the drive electrodes andthe display wiring in a display period, wherein the display wiring isdisposed closer to the display area than the touch wiring.
 2. Thedisplay device with a touch detection function according to claim 1,further comprising a first gate driver, a second gate driver, and aplurality of scan lines, wherein the first and second gate drivers aredisposed with the scan lines interposed therebetween in an extendingdirection of the scan lines, wherein the touch wiring includes firsttouch wiring on the first gate driver side and second touch wiring onthe second gate driver side, wherein the plurality of switches include aplurality of switches on the first gate driver side and a plurality ofswitches on the second gate driver side, wherein the scan lines includea plurality of first scan lines that intersect with the first touchwiring in a grade separation manner and a plurality of second scan linesthat intersect with the second touch wiring in a grade separationmanner, and wherein the switches on the first driver side are eacharranged in an area between adjacent first scan lines in the pluralityof first scan lines, and the switches on the second driver side are eacharranged in an area between adjacent second scan lines in the pluralityof second scan lines.
 3. The display device with a touch detectionfunction according to claim 2, wherein a distance between the adjacentfirst scan lines and a distance between the adjacent second scan linesare each larger than a distance between adjacent scan lines in theplurality of scan lines in the display area.
 4. The display device witha touch detection function according to claim 2, wherein a distancebetween the scan lines intersecting with the touch wiring in a gradeseparation manner is a distance between adjacent scan lines of theplurality of scan lines in the display area.
 5. The display device witha touch detection function according to claim 1, wherein at least twoscan lines in the plurality of scan lines are arranged between adjacentswitches of the plurality of switches in the plurality of switches. 6.The display device with a touch detection function according to claim 1,wherein each of the drive electrodes is provided corresponding to one ormore switches of the plurality of switches, and wherein the one or moreswitches provided for the drive electrode select either a connectionbetween the drive electrode and the display wiring or a connectionbetween the drive electrode and the touch wiring in a time-divisionmanner. The display device with a touch detection function according toclaim 1, wherein each of the switches is coupled to a correspondingdrive electrode with a first connecting conductor and coupled to acorresponding piece of the first and second touch wiring with a secondconnecting conductor.
 8. The display device with a touch detectionfunction according to claim 1, wherein the switches are divided into aplurality of switch groups that are provided corresponding to the driveelectrodes, and wherein each of the switch groups includes a firstswitch for applying a first voltage to a corresponding drive electrodein the drive electrodes and a second switch for applying a secondvoltage to the corresponding drive electrode.
 9. The display device witha touch detection function according to claim 1, wherein the displaywiring is provided with a direct-current voltage, and the touch wiringis provided with an alternating-current voltage.
 10. An electronicapparatus having a display device with a touch detection functioncapable of detecting an externally approaching object, the displaydevice with a touch detection function comprising: a display areaincluding a plurality of pixels arranged in a matrix on a substrate; aplurality of drive electrodes disposed to face at least one of thepixels; a display function layer that has an image display function todisplay an image in the display area; touch wiring that is routed in aframe area located outside the display area and supplies an alternatingcurrent touch drive signal to the drive electrodes; display wiring thatsupplies the display drive voltage; and a plurality of switchesconducting between at least one of the drive electrodes and the touchwiring in a touch detection period, and conducting between at least oneof the drive electrodes and the display wiring in a display period,wherein the display wiring is disposed closer to the display area thanthe touch wiring.
 11. The electronic apparatus according to claim 10,wherein the display wiring is provided with a direct-current voltage,and the touch wiring is provided with an alternating-current voltage.